fix: ignore event if account was already removed (#101)

* fix: ignore event if account was already removed

* test: add missing unit test (coverage)

src/SnapKeyring.test.ts

@@ -69,19 +69,17 @@ describe('SnapKeyring', () => {
       ]);
     });
 
-    it('throws when removing an account that does not exist', async () => {
+    it('returns null when removing an account that does not exist', async () => {
       mockCallbacks.removeAccount.mockImplementation(async (address) => {
         await keyring.removeAccount(address);
       });
 
-      await expect(
-        keyring.handleKeyringSnapMessage(snapId, {
+      expect(
+        await keyring.handleKeyringSnapMessage(snapId, {
           method: KeyringEvent.AccountDeleted,
           params: { id: 'bcda5b5f-098f-4706-919b-ee919402f0dd' },
         }),
-      ).rejects.toThrow(
-        "Account 'bcda5b5f-098f-4706-919b-ee919402f0dd' not found",
-      );
+      ).toBeNull();
     });
 
     it('fails when the method is not supported', async () => {

src/SnapKeyring.ts

@@ -21,7 +21,7 @@ import { CaseInsensitiveMap } from './CaseInsensitiveMap';
 import { DeferredPromise } from './DeferredPromise';
 import type { SnapMessage } from './types';
 import { SnapMessageStruct } from './types';
-import { strictMask, throwError, toJson, unique } from './util';
+import { strictMask, toJson, unique } from './util';
 
 export const SNAP_KEYRING_TYPE = 'Snap Keyring';
 
@@ -89,10 +89,17 @@ export class SnapKeyring extends EventEmitter {
 
       case KeyringEvent.AccountDeleted: {
         const { id } = params as any;
-        const account =
-          this.#getAccountById(id) ??
-          throwError(`Account '${id as string}' not found`);
-        await this.#callbacks.removeAccount(account.address);
+        const account = this.#getAccountById(id);
+
+        // We can ignore the case where the account was already removed from
+        // the keyring.
+        //
+        // This happens when the keyring calls the snap to delete an account,
+        // and the snap responds with an AccountDeleted event.
+        if (account !== undefined) {
+          await this.#callbacks.removeAccount(account.address);
+        }
+
         return null;
       }
 

src/util.test.ts

@@ -1,4 +1,4 @@
-import { ensureDefined, toJson, unique } from './util';
+import { ensureDefined, throwError, toJson, unique } from './util';
 
 describe('unique', () => {
   it('returns an empty array when given an empty array', () => {
@@ -52,3 +52,9 @@ describe('ensureDefined', () => {
     expect(() => ensureDefined(undefined)).toThrow('Argument is undefined');
   });
 });
+
+describe('throwError', () => {
+  it('throws an error with the given message', () => {
+    expect(() => throwError('hello')).toThrow('hello');
+  });
+});